Process and apparatus for the



Dec. 19, 1933.

C. W. P. HEYLANDT PROCESS AND APPARATUS FOR THE LIQUEFACTION 0F GASESOriginal Filed Nov. 29, 1927 53 3 INVENTOR ATTORNEYS Reissued Dec. 19,1933 PROCESS AND APPARATUS FOR THE LIQUEFACTION 0F GASES ChristianWilhelm Paul Heylandt, Berlin-Britz, Germany, assignor to 'FlugaAktien-Gesellschaft, St. Moritz, Switzerland Original No. Serial No.Germany 1,777,040, dated September 30, 1930, 236,401, November 29, 1927,and in December 29, 1926.

Application for reissue September 29, 1932. Serial No. 635,424

11 Claims.

The present invention relates to a process and apparatus fortheliquefaction of gases and has for its principal object to provide aprocess and apparatus for the recovery and conservation of gasesvaporized when liquefied gas is stored, transferred or transported.

More specifically, it is an .object to provide a process and apparatusfor reliquefying gases vaporized when a liquefied gas of low boilingpoint is stored and handled in air liquefying and separating plants.

Another object is to provide a process and ap paratus for recovering gaswhich is at too low a pressure for the desired purposes by utilizingother gas at a substantially higher pressure to increase to a desiredvalue the pressure of the gas to be recovered.

Another object is to provide a process and means for eliminating the useof large low pressure gasometers for recovering evaporation products.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the several steps and ,the relationof one or more of such steps with respect to each of the others, and theapparatus embodying features of construction, combinations of elementsand arrangement of parts which are adapted to eifect such steps, all

as exemplified in the following detailed disclosure,

and the scope of the application of which will be indicated in theclaims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken inconnection with the accompanying drawing, .in which:

Fig. 1 is a diagrammatic elevational view of means and exemplaryapparatus adapted for practicing the invention;

Figs. 2 and 3 are views partly in elevation and partly in section ofmodified forms of the apparatus. v e

In the operation of air-liquefying plants, as for example those forobtaining pure liquid oxygen, it has been customary heretofore to drawthe liquid from the air-liquefying apparatus into large storagecontainers and then to transfer the liquid from the latter-into othercontainers to be used as desired. To avoid, as far as practical, theloss of gas tothe atmosphere, such gases asare vaporized from the,liquefied gas when it is stored in containers at during the transferalcontainer to another,

relatively low pressure and of liquefied gas from one were recovered bycollecting them in large low pressure gasometers from which they weretransferred and compressed into suitable containers by means ofcompressors. The present invention avoids this inconvenient,

undesirable and expensive manner of handling the gases, by providing aprocedure whereby all gases which might otherwise escape are carriedback by suitable means to the liquefying apparatus to be reliquefied. Inthe preferred type of gas liquefying apparatus, the refrigerating lcapacity of the apparatus is sufllciently increased that the gas onbeing so returned will be liquefied. This can be effected by increasingthe pressure, for example, from a normal 200 atmos- Dheres to 250atmospheres, which causes the refrigerating capacity, especially of anexpansion'means, to be greatly increased, so that the final temperatureis decreased from 130 C. to 170 C. In this manner the completere-liquefaction of all gases returned to the column condenser iseffected and it is unnecessary to store such gas material in the gasphase at the producing plant.

Referring now to Fig. 1, 10 illustrates generally an air liquefying andseparating apparatus com- 30 prising a column of a type which has acondenser portion 11 and an evaporator portion 12. A liquefied gasstorage container 13 is shown associated with the column. This containerhas an outer jacket 13' and an inner vessel 14 (indicated 35 in brokenlines) for holding the liquefied gas, the space 15 between the innervessel and the jacket being of a heat insulating character. A containerfor storing and vaporizing liquefied gas of a type known as a coldconverter is also preferably employed and is shown generally at 27. Alow pressure container 43, adapted for storing and transportingliquefied gas, and of a character such that evaporation products mayarise therein, is shown operatively connected to the liquefyingapparatus.

In the apparatus here shown, conduit 16 provided with a valve 17, servesas a common connection whereby each of the containers above described isconnected to the liquefying apparatus 10. The conduit 16 is used for conucting liquefied gas out of the column 10 to each of the containers andfor transferring liquefied gas from one container to another. To thisend conduit 16 is detachably coupled to the liquid inlet of transportcontainer 43; and a valved connection 26 leads liquefied gas fromconduit 16 into container 2'7, while connection 41 between conduit 16and storage container 13 conducts liquefied gas in or out of the storagecontainer. Gas resulting from no the evaporation of liquefied gas ineach of the containers while said liquid is either in storage or in theprocess of filling and transferring liquid from one to the other isconducted back to the liquefying apparatus 10 by means of conduit 39,

which is also detachably coupled to the vapor outlet of transportcontainer 43. Conduits 40 and 42 connect the storage vessel 14 and thecontainerv2'7, respectively, to the conduit 39 for the purpose ofconducting the vapors from the containers to a point in the column 10abovethe liquid level inthe condenser portion 11.

It will be seen that the evaporation products resulting from the variousoperations in handling and storing liquefied gases are transferred tothe liquefying column 10 to be re-liquefied and that thereforesubstantially none will be' lost to the atmosphere and that the use of agasometer for collecting such gases is not required. I

In Fig. 2 is shown the storage container 13 with an outer envelope 13sectioned to show the inner vessel 14 and insulating space 15. A liquidconduit 18 leading from the liquid holding portion of vessel 14 passesup through neck 25 of vessel 14 and leads out to the liquefying columnwhich is not shown in this figure. A gas discharge conduit 19communicates with a coil20 surrounding the casing 13. The lower end ofcoil 20 by a connection 21 communicates with the lower end of a coil 22which surrounds the vessel 14 substantially spaced from its walls. Theupper end of coil 22 communicates with a coil 23 that is coiled aboutvessel 14 relatively close to its wall. The lower end of coil 23 is incommunication with the gas space of vessel 14 by means of a conduit 24.

A vaporizing container of a type known as a warm converter is showngenerally at 28. This container comprises a relatively heavy walledouter vessel 28' within which is suspended an inner vessel 35 forholding liquefied gas. Liquefied gas is conducted into vessel 35 bymeans of a valved conduit 29 which communicates with the liquid supplyconduit 18'. Gas which is vaporized in the warm container 28 normally isconducted out through conduit 42 and the branch which communicates withthe coiled conduit 34 around the upper portion of the warm container 28,from which it is conducted by valved conduit 30 into a gas receiver 48,where gas is stored at a relatively high pressure. The conduit 42, whichis provided with a valve in the portion beyond the branch to coil 34,conducts gas when desired to the low pressure gas conduit 39. Conduit 39conducts gas when desired to the liquefying column which is not shown inthis figure. 19 conducts gas from the coils 20, 22 and 23 of the storagecontainer 14 into conduit 39. A receiver 44 of fixed capacity is also incommunication with conduit 39 by means of valved conduit 45. Thereceiver 44 is used to store, when desired, gas which is collected inconduit 39 and to deliver the gas to conduit 39 again when desired.

A conduit 36 branches from conduit 30 and leads to a means for utilizingthe available energy of a gas at relatvely high pressure for drawingother gas from a source at relatively low pressure and compressing it toa desired pressure which is here shown in the form of aninjector 37. Thevalved conduit 36 conducts gas from the relatively high pressure sourceat 28 and 48 to the:

high pressure inlet of injector 3'7. A connection I 38 conducts gas fromthe conduit 39 into the suction chamber of injector 37. The gasesdischarged by the injector 3'7 are conducted by a The conduit conduit 49to a gas consuming device or to a gas liquefying apparatus or to thestorage receivers 3 46. A valved conduit 4'7 connects the receivers 46to conduit 49, so that gas may be conducted into or out of thereceivers, as desired.

Fig. 3 illustrates apparatus similar to tha shown in Fig. 2, except thatinstead of employing a container of the type shown at 28, there issubstituted the type shown at 27 in Fig. 1. The container showncomprises an external jacket 2'7 within which is disposed a liquefiedgas holding vessel 33. A heat insulating space substantially surroundsthe vessel 33 to insulate the same against the uncontrolled influx ofheat. A liquid discharge conduit 32 is coiled around the vessel 33- andjoins the lower end of an evaporating coil 31, which is wound around theouter jacket 27'. The valved conduit 30 is in communication with theupper end of coil 31. Liquefied gas is introduced into the coldconverter 2'7 by means of conduit 29 and gas is conducted when desiredout of cold converter 2'7 by means of valved conduit 42.

In the form of apparatus shown in Fig. 2, a supply body of relativelyhigh pressure gas is generated by filling the inner vessel 35 of thecontainer 28 with liquefied gas from conduit 18 through conduit 29, theliquid being conducted from either the liquefying apparatus not shown orfrom the body of liquid stored within storage container 13, and thedisplaced gas being conducted from the container 28 to conduit 39through conduit 42. When the inner vessel 35 is filled, the valves inconduits 29 and 42' are closed, and the valve in conduit 30 opened, andheat is permitted to reach the liquefied gas in vessel 35 through thewalls of the container 28, so that the liquid is vaporized at arelatively high rate and gas is conducted into and stored in receiver 48at a relatively high pressure for use when desired.

In the former vaporizing container shown in Fig. 3, the supply body ofrelatively high pressure gas is obtained in a similar manner by fillingthe container 33 with liquefied gas from the conduit 18 through conduit29, permitting the displaced and vaporized gases to escape to conduit 39through conduit 42. When it is desired to provide a supply of gas athigh pressure, the valves in conduits 29 and 42 are closed and the valvein conduit 30 opened and liquefied gas is withdrawn from vessel 33 intothe coil 32 and the evaporating coil 31, where it is vaporized andconverted .into gas at the desired pressure which is stored in receiver48.

The storage container'13, shown in both Figs. 2 and 3, cannot, withpresent commercially available means, be insulated suificientlyperfectly to avoid entirely the fiow of heat, though at a relatively lowrate, into the "body of liquefied gas stored therein, so that a smallamount of vaporization of the liquid occurs. These vapors are preferablyconducted through the coils surrounding the, inner vessel 14 and thenare conducted to conduit 39 through conduit 19. The gases which arecollected in conduit 39 are either led to the liquefying apparatus notshown or are led into receiver 44 through conduit 45, as desired. Whenit is desired to increase the pressure of such gases, the injector 37 isoperated. To this end, gas at high pressure is admitted through conduit36 to injector 37 where the energy of the high pressure gas is convertedinto kinetic energy which is transferred to gas that enters throughconnection 38 from conduit 39.

The velocity energy of the combined gases is transformed intoenergy ofpressure, so that the gas delivered to conduit 49 is of a desiredintermediate pressure. The gas at intermediate pressure is conductedinto and stored in receivers 46 through conduit 47, from which it isdis: charged when desired to consuming apparatus not shown. When the gascollected in conduit 39 is of too low a pressure to flow to theliquefying apparatus, the injector 37 may be operated to raise thepressure to the desired value, so that the gas may be conducted to theliquefying apparatus through conduit 49.

It will be seen that by the use of the injector 37, gases which are attoo low a pressure for desired purposes maybe drawn out of any of thecontainers and forced into containers 46 and to consuming apparatus, orto the liquefying apparatus.

From the foregoing, it will be seen that the. connection of a container,such as a container for withdrawal products, a stationary ortransportable container for liquefied gas, with a gas liquefyingapparatus by means of conduit connections, whereby the products arisingby evaporation of the liquid handled may be returned, is an essentialcharacteristic of the present invention. By such direct return, it willalso be seen, that use of storage gasometers and of compressors, asheretofore commonly employed, is done away with together with theaccompanying losses, whereby the overall efi'iciencies of productionplants are materially increased.

Since certain changes in carrying out the above process and in theconstructions set forth, which embody the invention, may be made withoutdeparting from its scope, it is intended that all matter contained inthe above description or shown in the accompanying drawing shall beinterpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desireto secureby Letters Patent, 1s:

1. The'method of conserving evaporation products arising from liquidoxygen when held in storage containers and the like; which comprisesreturning said evaporation products from said container to an airliquefying and separating apparatus, and liquefying the returnedproducts by increasing the refrigerating capacity of said apparatus.

2. The method of conserving evaporation products arising from liquidoxygen when held in storage containers and the like, which comprisesreturning sagl evaporation products from said container to an airliquefying and separating apparatus, and liquefying the returnedproducts in said apparatus by increasing the pressure from about 200atmospheres to 250 and decreasing the temperature from about -130 C. toabout 170 C.

3. The method of conserving evaporation products arising from liquefiedgases held in containers which comprises returning said evaporationproducts from a container toa gas liquefying apparatus, and liquefyingthe returned products by utilizing Within said apparatus the pressureresulting from the temporary storage within said container of saidproducts of evaporation.

t. The'method of conserving evaporation produc s arising from liquefiedgases held in containers which comprises returning said evaporationproducts to a gas liquefying apparatus, utilizing the available energyof the returned products for the liquefaction of gas, and increasing thepressure to a Value desired for consumption.

5. The process of liquefying gases evaporated within clos'ed pressuretanks, which consists in introducing said gases into a distributingsystem operating under diiferent degrees of pressure, and utilizing theincreased pressure resulting from the transition from the liquid to thegaseous state for raising the tension of low-pressure gases and viceversa.

6. Apparatus for recovering gas vaporized from a low boiling pointliquefied gas comprising a gas liquefying and separating apparatusincluding a refrigerating portion, liquefied gas storage meansassociated therewith, a liquefied gas container, means for supplying gasunder pressure to 0001 said refrigerating portion-by gas expansion, andconduit connections for transferring liquefied gas and for conductinggas vaporized from liquefied gas into the refrigerating portion of saidapparatus.

7. Apparatus for recovering gas vaporized from a low boiling pointliquefied gas comprising a gas liquefying and separating apparatusincluding a refrigerating means, a filling container communicatingtherewith, a storage container for liquefied gas in communication withsaid filling container and apparatus a transportable container also incommunication with said filling container and apparatus, and means forintroducing gas under relatively high-pressure to said refrigeratingmeans to produce a refrigerating effect therein including vapor returnconnections leading from said containers. I g 8. Apparatus forrecovering gas vaporized from liquefied gas comprising a gas liquefyingapparatus, a liquefied gas container and a refill device incommunication with said apparatus, a supply container connected withsaid liquefied gas container, means for utilizing in said refill devicethe pressure generated in said supply container, and means actuated bysaid pressure for increasing the gas pressure in portions of saidconnected appara-' tus and reducing the pressure in the remainingportions.

9. Apparatus for recovering gas vaporized from liquefied gas comprisinga gas liquefying appara-- tus, a low pressure container and a highpressure container connected to communicate with said apparatus,additional containers of the pressure type connected with said lowpressure container, the connections being such that the evaporationproducts arising from said low pressure container are operative togenerate high pressure in said high pressure container, and injectorsdisposed tain of said containers andreducing the pressure in theremaining containers.

10. Apparatus for liquefying evaporation products resulting from theoperation of liquefied-gas containers, comprising a gas-supplying systemadapted to operate under different pressures, gasifiers, pipe linescommunicating with said system and gasifiers, injectors disposed insaid, pipe lines, pressure tanks connected with the high and lowpressure sides of said gasifiers', and means for causing thehigh-pressure gases from the gasifiers to actuate said injectors therebyto reduce the pressure in the low-pressure tanks and increase thepressure in the high-pressure tanks.

11. Apparatus for liquefying evaporation products resulting from theoperation of liquefied-gas containers, comprising a gas-supplying systemadapted to operate under difi'erent pressures, gasifiers, pipe linescommunicating with said system and gasifiers, injectors disposed in saidpipe lines, pressure tanks connected with the high and low pressuresides of said gasifiers, means for causing the high-pressure gases fromthe gasifiers to actuate said injectors thereby to reduce the pressurein the low-pressure tanks and increase the pressure in the high-pressuretanks, and means for storing up in said low-pressure tanks the gasesgenerated in the gasifiers by. natural evaporation.

CHRISTIAN WILHELM PAUL HEYLANDT.

